Tickling rats as a positive welfare indicator

Funder and dates: BBSRC

Collaborators/partners: SRUC, University of Edinburgh and INRA- Paris

Abstract/brief outline

It is now widely recognised that good animal welfare means more than simply the absence of negative experiences, such as pain or fear. As such, there has been growth in research investigating positive emotional states experienced by animals and how they might be assessed. However, since animals cannot tell us how they are feeling, how do we assess if they are “happy”? Play behaviour has long been proposed as a promising potential indicator of positive welfare and emotions. One of the most studied and well characterised forms of play behaviour is “rough-and-tumble” social play in adolescent rats. The tickling paradigm was developed to mimic this social play between a human experimenter and a rat. During both play and tickling, rats emit ultrasonic vocalisations of a specific frequency, out of human hearing range. These vocalisations are thought to reflect a positive emotional state, originally termed as “laughter” and could potentially indicate when animals are experiencing positive welfare.

Rat 'Laughter' Vocalisations

Project outcomes

We (SRUC, Roslin and INRA-Paris) have successfully developed a protocol for rat tickling (see video here), and have been investigating the effect of anxiety and physical condition on response to tickling, as well as the relationship of tickling with play behaviour.

Linked with the study on play behaviour in farm animals, future work looks to support the use of the rat tickling model as a benchmark for the study of positive emotions and welfare in both lab and domesticated animals. Ultimately, the main goal is to be able to apply these methods in both experimental and practical animal handling and housing contexts.

We are also looking to use tickling as a model of social pay to improve our understanding of the impact of positive emotional states on the brain and physical health.